A method of this type for introducing a vertical shaft underground as well as a shaft boring machine are known from the JP 2006249793 A. In the prior art method and the prior art shaft boring machine a rotatable cutterwheel is rotated continuously about a horizontal axis and a central vertical axis such that a shaft floor is excavated in a substantially even manner over the entire area of the walls.
Another method for introducing a vertical shaft and a shaft boring machine are known from the U.S. Pat. No. 4,646,853. The prior art method for introducing a vertical shaft underground provides a shaft boring machine having a rotatable cutterwheel which can he rotated about a horizontal axis and about a vertical axis at a distance from a central longitudinal axis of the shaft boring machine. By this means, the cutterwheel follows a vertical spiral path such that it continuously excavates a shaft floor wider than the diameter of the cutterwheel.